We reveal the relationship between the light enhanced moisture degradation and the photostriction effect in MAPbI ₃ perovskite.

The photoluminescence performance of Cs ₂ AgInCl ₆ is enhanced by the Mn dopant via transition from the ⁴ T1 state to the ⁶ A ₁ state.

Carrier mobility is one of the most important parameters for semiconducting materials and their use in optoelectronic devices. Here we report a systematic first principles analysis of the acoustic phonon scattering mechanism that limits the mobility of CH₃NH₃PbI₃ (MAPbI₃) perovskites. Due to the unique hybrid organic-inorganic structure, the mechanical, electronic and transport properties are dominated by the same factor, i.e. the weak interatomic bond and the easy rotation of methylammonium (MA) molecules under strain. Both factors make MAPbI₃ soft. Rotation of MA molecule induces a transverse shift between Pb and I atoms, resulting in a very low deformation potential and a strong piezoelectricity in MAPbI₃. Hence the carrier mobility of pristine MAPbI₃ is limited by the piezoelectric scattering, which is consistent to the form of its temperature dependence. Our calculations suggest that in the pristine limit, a high mobility of about several thousand cm² V⁻¹ S⁻¹ is expected for MAPbI₃.

For the potential applications in spintronics, we examine systematically the electronic properties of group-V elements (X) doped ZnO to investigate the magnetic properties induced by X based on density functional theory calculations. Our results indicates that X atoms doped in the form of a substitutional X atom at an O anion site (X_O) and at a Zn cation site combining with two Zn vacancies (X_Zn–2V_Zn complex) under different circumstances can introduce magnetism. The magnetism comes from the p–p and p–d coupling interaction between the dopant X-p orbitals and the host O-2p and Zn-3d orbitals. The stability of the ferromagnetism (FM) phase induced by X_O defects decreases with the increase of dopant atomic number due to the lower electronegativity value, which can be interpreted by the phenomenological band-coupling model. The origin of the magnetism induced by X_Zn–2V_Zn is similar to that of the Zn vacancy (V_Zn) in ZnO and comes from the O-2p orbitals dominantly. The FM stability introduced by X_Zn–2V_Zn decreases with the order N < Sb < As < P, which is ascribed to the delocalization of the O-2p orbitals. The results mean that 3p/4p/5p dopants could also make ZnO materials into diluted magnetic semiconductors.

Perovskite single crystals have attracted tremendous attention owing to their excellent optoelectronic properties and stability compared to typical multicrystal structures. However, the growth of high‐quality perovskite single crystals (PSCs) generally relies on temperature gradients or the introduction of additives to promote crystal growth. In this study, a vacuum evaporation crystallization technique is developed that allows PSCs to be grown under extremely stable conditions at constant temperature and without requiring additives to promote crystal growth. The new method enables the growth of PSCs of unprecedented quality, that is, MAPbBr₃ single crystals that exhibit an ultranarrow full width at half maximum of 0.00701°, which surpasses that of all previously reported values. In addition, the MAPbBr₃ single crystals deliver exceptional optoelectronic performance, including a long carrier lifetime of 1006 ns, an ultralow trap‐state density of 3.67 × 10⁹ cm⁻³, and an ultrahigh carrier mobility of 185.86 cm² V⁻¹ s⁻¹. This method is applicable to various types of PSCs, including organic–inorganic hybrids, fully inorganic structures, and low‐dimensional structures.

High-quality MAPbBr₃ single crystals were successfully synthesized using the vacuum evaporation crystallization method for the fabrication of X-ray detectors, demonstrating an ultra-low detection limit and exceptional sensitivity.